Organosilicon compounds



Patented Aug. 28 1945 I OBGANOSILICON OOMPQUNDS Eugene G. Rochow,Schenectady, N. Y., asslgnor to General Electric Company, a

New York corporation of No Drawing. Original application April 30, 1940,l

Serial No. 332,606. Divided and this application March 24, 1942, SerialNo. 435,938

7 Claims.

This invention relates to new compositions of matter and moreparticularly to new and useful organo-silicon compounds. Specifically,the invention is concerned with the-production of organo-siliconcompounds in which a plurality of divalent organic radicals are eachlinked to two separate (different) silicon atoms. This application is adivision of my copending application Serial No. 332,606, filed April 30,1940, and assigned to the same assignee as the present invention. Theclaims in the present application are directed to organo-siliconcompounds 01' the designated type in which some of the organic radicalsare replaced by oxygen.

Compounds of silicon, oxygen, and divalent organic radicals heretoforehave been known. Bygden (Berichte, 48, 1236, 1915, and DissertationUpsala, 1916, 105-107) prepared pentamethylene silicone, [(CH2)5SiO]:,by hydrolysis of pentamethylene silicon di-chloride'to the correspondingsilicol which, when dehydrated, yielded the silicone. This material is asubstituted silicon oxide and is solid and polymeric by virtue of the--SiO-Si network. In polymeric pentamethylene silicon, thepentamethylene radicals are attached to the silicon atoms in thismanner:

As will be seen from the above formula, each divalent pentamethyleneradical is attached to a single silicon atom.

In marked contrast with the known pentamethylene silicone, the newcompounds of this invention are polymeric bodies in which a large numberof silicon atoms are linked to one another by divalent (double-ended)organic radicals in this manner: (A)

In the above formula, which for purposes of clarity has been shown as adoubling of the unit structure,

R represents any divalent organic radical capable of being linkedthrough each of its two valences to separate silicon atoms. Forinstance, when R in Formula A represents an aromatic radical,specifically a phenylene radical, the polymers of this invention containthe structure OrQnm may be Similarly, when R in Formula A represents asaturated aliphatic radical such as a methylene or poly-methyleneradical, specifically -CH:-, the polymers of this invention contain thestructure Illustrative examples of other divalent organic radicals whichR in Formulas A and B maybe are dimenthylene, (CH2) z--, trimethylene,

-(CH:):, tetramethylene, --(CH2)4, pentahexametbylene, -(CH2) c, or ingeneral any aliphatic straight methylene, (CH=)s-,

chainradical of the general type, (CH2)=, where :r is any integer, forexample from 1 to 20 or more. Other examples of divalent organicradicals which B. may be are p,p'-diphenylene,

the aliphatic branched chain radicals, for intuted phenylene radicals ofthe general type. CH3R', where R is any alkyl or aralkyl substituentradical; aryl-substituted alkyl radicals, e. g., substituted radicals ofthe general type,

where R" is any aryl or alkaryl radical. More specific examples ofradicals which R and R" may be are given hereafter with particularreference to monovalent organic radicals.

In the polymeric bodies described by Formula A the divalent organicradicals designated generallyasRneednotallbethesa-me. Fore!- ample one Rmay be --(CH:)1- and another R maybe an aliphatic branchedchain'divalent i c a methyl methyl ne, a substituted or unsubstitutedphenylene radical, a polymethylene,

radical, etc. A more specific example of this type of compound is onecontaining approximately an equal number of pentamethylene and phenyleneradicals bonded to silicon atoms. In such a polymer the silicon atomsand divalent organic radicals are bonded together in the followingrandom manner:

alkaryl, aralkyl, etc., radicals. Polymers of this type contain thestructure A o i n% iB-Si etc.

where R represents the same or diilerent divalent organic radicals and Arepresents the same or difierent univalent organicradicals. From thisformula it will be seen that ii the divalent radicals are replaced bytwice the number of monovalent radicals to yield a product having thestructure A A n -B+ i-R- sietc.

a linear polymer incapable of cross-linking, that is, incapable offorming a three-dimensional network, is obtained. In these compounds ofsilicon with monovalent and divalent organic radicals, the averagenumber of monovalent radicals should not be greater, and preferably isless, than twice the average number of divalent radicals. Byproportioning the reactants so that the average number of monovalentradicals is less than twice the average number oi divalent radicals,cross-linking can take place during polymerization of the compound toyields. more rigid structure. Illustrative examples of monovalentorganic radicals which A in the above formulas may be are methyl, ethyl,propyl, isopropyl, butyl, isobutyl, amyl, hexyl, heptyl to octadecyl andhigher in the aliphatic series; halogenated and nonhalogenated arylradicals, e. a. phenyl. monoand polyalkyl phenyl as for instance tolyl,xylyl. mono-, diand tri-ethyl phenyl,.also naphthyl, alkyl naphthyl, (e.g., methyl naphthyl), tetrahydronaphthyl, anthracyl, benzyl, etc.

Organo-silicon compounds formed of divalent organic radicals linked tosilicon (or formed of monovalent and divalent organic radicals linked tosilicon) and wherein some of the organic radicals have been replaced byoxygen also may be produced in accordance with this invention. In suchmodifications the number of oxygen atoms should not be greater than anaverage of one for each two silicon'atoms, that is, the number of oxygenatoms should not exceed one-half oxygen per silicon atom. Polymers ofthis type contain, for example, the structures *1 where A and R have themeanings above given.

Any suitable method may be employed in preparing my new compositionscomprising an organo-silicon compound in which a. plurality of divalentorganic radicals are each linked to two dlflerent silicon atoms. Forinstance, such compounds may be prepared by efiecting reaction between asilicon halide (e. g., silicon tetrachloride, silicon tetrabromide,etc.) and at least two molecular equivalents of the di-magnesiumderivative of the iii-halides (e. g., di-chlorides, dibromides anddi-iodides) of divalent organicradicals such as above named by way ofexample.

In order that those skilled in the art better may understand how thepresent invention may be carried into client, the following illustrativeexamples thereof are given:

Example 1 This example illustrates a. method of preparing a polymericbody of the type represented by Formula A and, specifically, Formula F.The method or preparation was as follows:

1. One and sixty-five hundredths 1.65) mols of p-dibrombenzene in ethersolution was caused to react with 3.45 mols magnesium, resulting in atwo-phase system containing 1.32 mols of phenylene ell-magnesiumbromide:

2. The solution of phenylene di-magnesium bromide was added slowly, withstirring, to an ether solution of 1.32 mols of silicon tetrachloride andthe reaction mixture was heated under reflux for 30 minutes, yielding aphenylene silicon dichloride:

3. One and thirty-two hundredths (1.32) mols of the (Ii-magnesiumderivative of mixed isomeric dlchlorpentanes in ether solution were thenadded, with stirring, to the reaction mixture of step 2, and theresulting mass wes'heated under refiux for 2 hours.

4. The solution of organo-silicon compoimd isolated by pouring theentire reaction mass into water, thereby dissolving out the magnesiumsalts.

Most of the ether was evaporated to yield an extremely viscous,benzene-soluble, yellow resin. Upon evaporation or all the ether thereresulted a solid, clear, yellow resin having a nontaclry surface.

The product oi. this example may be described as a reaction product or asilicon halide, specifically silicon tetrachloride, with two molecularequivalents of the di-magnesium derivatives of two organic di-haiides,specifically a di-chloride and a di-bromide.

Example 2 4. The solution of methyl phenylene silicon was isolated bypouring the entire reaction mass into water, thereby dissolving out thema nesium salts. The ether layer was separated and washed free ofmagnesium salts. The removal of the ether left a brown, sticky resinwhich melted at approximately 100 C. It was insoluble in alcohol, butsoluble in benzene and acetone. Heating for 5 hours at 230 C. did notsolidify the molten resin nor cause any apparent physical change.

The product of this example may be described as a reaction product of asilicon halide with one molecular equivalent of the di-magnesiumderivative of an organic di-halide and slightly more than two molecularequivalents o f'the magnesium derivative of an organic mono-halide.

Example 3 This example illustrates a method of preparing a polymericbody of a type similar to that represented by Formula J. The method ofpreparation was as follows:

The first two steps of the pl'OCBS were essentially the same as thosedescribed under steps 1 and 2 of Example 1.

3. An ether solution of methyl magnesium bromide containing 1.26 molsmethyl magnesium bromide per mol phenylene silicon dichloride was addedslowly, with stirring, to the reaction mass resulting from step 2. Themain reaction is:

4. The methyl phenylene silicon chloride was hydrolyzed by pouring thereaction mass on Theether' layer containing the hydrolysis product wasseparated and washed free of acid. Evaporation of the ether yielded asoft, sticky, yellow, resinous material.

' 5. The product of step 4 was condensed (dehydrated) by heating thematerial at a gradually increasing temperature to C. After two hoursheating at 110 C. the product was still liquid, but solidified whenheated for an additional hour at C. This condensation product was asoft, brown resin. It was soluble in benzene, toluene, and acetone. Thisresin became infusible on prolonged heating.

If desired, the condensation reaction may be carried out in the presenceof a dehydrating agent, e. g., an alkyl borate such as ethyl borate.Illustrative examples of other dehydrating agents which may be employedto accelerate the condensation reaction are disclosed in mycopendiigioapplication Serial No. 332,605, filed April 30, 1

The product of this example may be described as a resinous dehydratedproduct of hydrolysis of the reaction product of more than one and lessthan two molecular equivalents of the magnesium derivative of an organicmono-halide, specifically 1.26 mols methyl magnesium bromide, with theproduct of reaction of a silicon halide with one .molecular equivalentof the di-magnesium derivative of an organic di-halide, specificallyphenylene di-magnesium di-bromide.

It will be understood oi course that my invention is not limited to thespecific methods shown in the above illustrative examples, nor to thespecific reactants and proportions therein shown.

In accordance with this invention chemical compounds consisting of aplurality of monovalent and divalent organic radicals linked to siliconatoms may be prepared by reacting, for example, a solution oi a siliconhalide with a solution containin one molecular equivalent of thedi-magnesium derivative of an organic dihalide, reacting the resultingsolution of organosilicon halide with a solution containing twomolecular equivalents of the magnesium derivative of an organicmono-halide, and isolating from the reaction mass the organo-siliconcompound thereby produced. In preparing compounds of silicon withdivalent organic radicals and oxygen, a suitable method, for example,comprises effecting reaction between a silicon halide and more than 1 /2but less than 2 molecular equivalents of the di-magnesium derivative ofan organicdi-halide, hydroLvzing the resulting product and dehydratingthe hydrolyzed product in the presence or absence of an accelerator ofcondensation, e. g., a dehydrating agent.

As is evident from the above description of the compounds of the presentinvention, particularly from their method of preparation, the novelcompounds are further characterized by the fact that they contain noSi-Si linkages, the silicon atoms being connected to one another bydivalent organic radicals or oxygen atoms.

To illustrate how the resinous materials of this invention may be usedin industry, the following examples are cited:

A liquid coating composition comprising a volatile solvent and asoluble, heat-hardenable liquid, or a normally solid, resinous polymer,such as above described, is applied to a metallic conductor such ascopper wire. Thereafter the coated wire is heated to vaporize thesolvent and to harden the polymer. In this way the polymerization of theresin may be continued or completed in situ. In manufacturing certainkinds of electrical cables itmay be desirable to wrap the conductor withan organic or inorganic fibrous material such as asbestos, glass, cottonor paper before treating it with the liquid resin. A further procedureis to coat and at least partly impregnate the wrapped conductor with theliquid resin, wind the thus insulated conductor into the desired coil,and then heat the wound coil to solidify the resin.

Sheet insulation may be prepared by treating woven or felted organicfabrics or paper with compositions comprising the herein-describedresinous materials. Sheet insulation also may be prepared by bindingflaky inorganic substances with these new resins. For example, they maybe used in the production of laminated mica products comprising micaflakes cemented and bonded together with the polymerized resin.Self-supporting coherent films or sheets of clay such as bentonite alsomay be treated to advantage with compositions comprising the polymericbodies of this invention. Such treated films may be produced asdescribed more fully in, for example, my copending application SerialNo. 287,787, filed August 1, 1939.

In addition to their use in the field of insulation, these new resinouscompositions also may be used as protective coatings, for instance ascoatings for base members such as glass bulbs or other articles ofglass, also for coating metals such as iron, steel, copper, etc. Theyalso may be used as sealing compositions in the production of socalledresistance or semi-conducting paints, and for other commercialapplications as described more fully in my copending applications SerialNos. 287,787 and 296,819, filed September 27, 1939, with particularreference to methyl silicones and halogenated aryl silicones.

In certain cases it may be desirable to form mixtures of differentpolymers of this invention. In other cases, difierent products capableof being dehydrated or condensed may be mixed and.

co-condensed to yield resins better adapted for a particularapplication. However, in such cases the components should be mixedbefore the condensation of the individual materials has advanced to thepoint where the bodies are incompatible, For other applications it maybe desirable to polymerize or condense the liquid resins to solid formand then mix and grind the materials together to form a composite mass.

The polymerizable or the polymerized resins of this invention also mayhave incorporated therewith various other materials, for examplepolymerizable or polymerized silicones. Examples of compounds which thusmay be used to modify the resins of this invention are those describedin my copending applications Serial Nos. 287,787; 296,819; filedrespectively August 1 and September 2'7, 1939, and in applicationsSerial Nos. 332,097, 332,098, and-332,099 filed April 2'7, 1940, all ofthese applications being assigned to the same assignee as the presentinvention. Thus. polymerizable compositionsmay be prepared by mixingpolymerizable silicones such for example as polymerizable methylsilicones, halogenated or nonhalogenated aryl silicones, aroxyaiylsilicones,

methyl aryl silicones, etc. with the herein described polymers orpartial condensation prod ucts. The resulting polymerlzable mixturesthen may be polymerized under heat or under heat and pressure, and inthe presence or absence of a polymerization catalyst, to obtain productshaving properties difierent from the separately polymerized components.Also, if desired, polymeric silicones such as those mentioned above maybe suitably compounded with the polymerizable or p lymerized resins ofthis invention. In these and other ways the basic materials of thisinven tion may-be modified to provide products having properties bestadapted for a particular service application.

The individual copolymerized or mixed liquid, semi-solid or solidsilicon-containing resins of my invention may be suitably incorporatedinto other materials to modify the properties of the latter. Forexample, they may be compounded with substancesv such as natural andsynthetic rubber; tars. asphalts and pitches, more specific examples ofwhich are wood tars, petroleum asphalts and vegetable pitches, naturalresins such as wood rosin, copal, shellac, etc.; synthetic resins suchas phenol-aldehyde resins, urea-aldehyde resins, modified and unmodifiedalkyd resins, cumar resins, vinyl resins, esters of acrylic andmethacrylic acids, etc. cellulosic materials such as cellulose nitrate(pyroxylin) cellulose acetate including the triaceate, cellulosepropionate, cellulose butyrate, etc., cellulose ethers such as methylcellulose, ethyl cellulose, benzyl cellulose, etc. In some cases thehard polymers of this invention may be pulverized and used as fillersfor substances such as above mentioned. In other cases, especially whenthe silicon resin is compatible with the substance with which it is tobe incorporated, it may be in the form of a liquid or relatively softpoly- 4 mer of low molecular weight prior to compounding with thesubstance tobe modified.

These new silicon resins also may be compounded with various othermaterials. For example. the hard, brittle polymers may be plasticized bythe addition of suitable plasticizing materials or the liquid orlow-softening-point polymers themselves may be used as plasticizers ofother normally brittle substances.

no The low molecular weight resinous polymers of this invention also maybe dissolved or dispersed in oils, such as linseed oil, Chlnawood oil,perilla oil, soya bean oil, etc., alone or mixed with solvents,pigments, plasticizers, driers, and other compounds of coatingcompositions to yield products which, when applied to a, base member andair-dried or baked, have improved heat resistance.

Laminated products may be made by superim-v posing organic or inorganicfibrous sheet materials coated and impregnated with these new resins andthereafter bonding the sheets together under heat and pressure. Moldingcompositions and molded articles also may be formed from these newresins. If desired, filling materials such as asbestos, glass fibers,talc, quartz powder,

" wood fiour, etc., may be incorporated into such compositions prior tomolding. Shaped articles are formed from such compositions under heat orunder heat and pressure in accordance with practices now widely used inthe plastics arts.

What I claim as new and desire to secure by Letters Patent of the UnitedStates, is:

l. A polymeric organo-silicon compound comprising oxygen atoms anddivalent aromatic radicals linked to silicon atoms, the said compoundcontaining no Si-si linkages each of a plurality of said oxygen atomsand divalent aromatic hydrocarbon radicals being linked to two difierentsilicon atoms, the oxygen atoms in said compound not exceeding anaverage of one for each two silicon atoms.

2. A composition comprising a resinous organosilicon compound containingno Si--Si linkages and consisting of monovalent hydrocarbon radicals,divalent aromatic hydrocarbon radicals and oxygen atoms linked tosilicon atoms, each of a plurality of the divalent hydrocarbon radicalsand oxygen atoms linking two different silicon atoms, the said oxygenatoms in said compound not exceeding an average of one for each twosilicon atoms, the said monovalent radicals being selected from theclass consisting of saturated aliphatic hydrocarbon radicals andaromatic hydrocarbon radicals.

3. The method of preparing a chemical compound consisting of a pluralityof oxygen atoms, monovalent hydrocarbon radicals and divalent aromatichydrocarbon radicals linked to silicon atoms which comprises reacting asolution of a silicon'tetrahalide with a solution containing onemolecular equivalent of the di-magnesium derivative of dihalogenatedaromatic hydrocarbon, re-

acting the resulting solution of organo-silicon halide with a solutioncontaining more than one but less than two molecular equivalents of themagnesium derivative of a monohalogenated hydrocarbon selected from theclass consisting of saturated aliphatic hydrocarbon and aromatichydrocarbons, hydrolyzing the resulting product and dehydrating thehydrolyzed product.

4. A polymer comprising oxygen atoms and phenylene radicals linked tosilicon atoms, each of a plurality of the oxygen atoms and phenyleneradicals being linked to two different silicon atoms, the said polymercontaining no Si-Si 5 linkages, the number of oxygen atoms in the saidpolymer not exceeding an average of one for each two silicon atoms.

5. A polymer consisting of methyl radicals, phenylene radicals andoxygen atoms linked to in silicon atoms, each of a plurality of thephenylene radicals and oxygen atoms linking two difierent silicon atoms,the said polymer containing no Si-Si linkages, the said oxygen atoms insaid polymer not exceeding an average of one for each 15 two siliconatoms.

6. A polymericcompound consisting of monovalent saturated aliphatichydrocarbon radicals, phenylene radicals and oxygen atoms linked tosilicon atoms, each of a plurality of the phenylene 2U radicals andoxygen atoms being linked to two 35 EUGENE G. ROCHOW.

Certificate of Correction Patent No. 2,383,817. August 28, 1945. EUGENEG. ROCHOW.

It is hereby certified that errors appear in the printed specificationof the above numbered patent requiring correction as follows: Page 1,first column, line 31, in the formula, strike out the double bond in thelast portion thereof and insert instead a sin le bond; and secondcolumn, line 2, for "valences read valenc'ies; lines 17 to 21 1n usive,strike out the formula and insert instead the following:

-'-ctn I can l-eta':

' lines 28 to 30 strike out the formula and insert instead thefollowing:

7 CH Iieta,

- and line 33, for "dimenthylene" read dimethyleneifziem first column,lines 45 to 48 inclusive, strike out the formula and insert instefollowing:

g e 3, second column, line 27, for "Seriai read Serial; and that thesaid Letters atent should be read with these corrections therein thatthe same may conform to the record of the case in the Patent Oflice.

Signed and sealed this 25th day of December, A. D. 1945.

LESLIE FRAZER,

First Assistant C'mnmisciomr of Patents.

